Field of the Invention
The present invention relates to a technique for assisting in capturing a panning shot.
Description of the Related Art
A panning shot technique is known as a shooting technique that expresses a sense of speed for a moving subject. This shooting technique is to capture a moving subject so that it appears to be still while the background appears to be moving, due to a user panning a camera so as to follow the motion of the subject. Ordinary panning shots are captured by adjusting an exposure time to be longer than an ordinary exposure time, according to the moving speed of a subject to be captured.
In capturing a panning shot, a user needs to perform panning so as to follow the motion of the subject, and if the panning speed is too high or low thus creating a difference between the panning speed and the moving speed of the subject, it will often be the case where the image of the subject is also blurred. In order to solve such a problem, a technique for eliminating a difference between the moving speed of the subject and the panning speed by moving a shift lens for correcting hand shake has been proposed as a technique for assisting a user in capturing a panning shot. For example, Japanese Patent Laid-Open No. 2006-317848 discloses a configuration that captures a panning shot in which shaking of an apparatus is detected by a gyro-sensor, a subject is detected based on motion vectors of an image, a correction amount for positioning the detected subject at the center of the image is calculated, and the correction is performed by moving an optical axis shift lens. Japanese Patent Laid-Open No. 2003-279848 discloses a configuration in which an image is divided into a plurality of regions, and a main subject is detected based on the subject brightness and the subject distance, capturing magnification, and subject movement distribution that are detected for each region.
However, in the technique disclosed in the above-described Japanese Patent Laid-Open No. 2006-317848, shaking of the apparatus is detected by the gyro-sensor, and a subject is detected based on motion vectors of an image. Therefore, in a case, for example, where a subject is approaching a user or there are a plurality of subjects, there is the problem that a plurality of motion vectors that have similar magnitudes and orientations may be detected, and it is difficult to suppress blurring of a subject at a position that is desired by the user to appear to be still.
Also in the technique disclosed in Japanese Patent Laid-Open No. 2003-279848, if a user tries to capture a panning shot in a case where there are a plurality of moving subjects, it will be difficult to appropriately detect the subject that is desired by the user to appear to be still when the panning speed of the camera differs from the moving speed of the subject, because the technique does not take into consideration the influence of panning of a camera.